All new investments (including follow-on by existing investors) are subject to 12 month holding period
That doesn't match what I was told. I have sent an email to Grayscale asking for clarification and will post the response here when I get it.
My bad; per Rule 144
http://www.investopedia.com/terms/r/rule144.asp there is a 12 month holding period effectively making arbitrage way too slow.
It will be an interesting dynamic for GBTC if the Winklevoss ETF (COIN) suddenly gets traction.
As COIN is going through a full listing process instead of relying on the 144 loophole, it will not have the same arbitrage issues as with GBTC. So it should have very little - or at least, much less - spread between market price and NAV.
And COIN will be purchasable in the same 401k / Roth / IRA accounts as GBTC. And those accounts grow tax free, so you won't take a tax hit if you sell GBTC to buy COIN.
So once COIN is trading, the GBTC premium should evaporate.
However, if COIN starts to show traction, bitcoin may have a run, and GBTC's premium might be maintained for some period of time by people who want to capture that run without buying bitcoin directly, or if 401k type accounts.
